since unixy OSes have recently adopted TOCTOU-resistant path operations like `openat` and friends, has there been any consideration of doing something similar for the current executable? seems like it would be useful for a process to be started with the fd the image was mapped out of available to it, with `execat`/`posix_spawnat` syscalls to open an executable by fd rather than by path, so that you don't have to reconstruct the current executable path and hope it didn't change under you